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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '139e251d8a2ebce5707006a2d4504d29ee895183d3bc8553f3bc1a9c4ccb79ba' 
  AND token = 'ctMVX4CsC757bCT13mzOYT4GXQeFXppx6yAwq4zba+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}