SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4f70f0fc9f6181a27171cd27651358fb63a2e85967b927fd54ad2f88af4b517' 
  AND token = 'R5Mx6EAYhtkr2eKnE1KIbSblgtQUJSWgKRqjYB/+jHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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