SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18b5031632db2c550230da40fb3c3b94f9962689e403ba6046191b1b92541c48' 
  AND token = 'YZNAcQr//NKcbgOriVKvUSXPITJUYLyTrvCuqduwqSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}