SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adc4d37d1be73b2c17a434ffcbc847bf2ffcfd3077fbe7368bce812b74062ef7' 
  AND token = 'SIgb9m4wX3IGeyWO5dnHTK+X6EMWQ5OqGsioc91ZaKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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