SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caeee7d0cbbcb54d9518daeec85a07f38c689406ab7bf190e98050e7396ab7be' 
  AND token = '9LLVUCjwJhMECtL1INjq5oZAEkZzUfHhwrYG2CyUDx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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