SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9db7d739b37b03b21782fa9a8725433938697ee04061fba4baa6073e74379746' 
  AND token = 'Pvg9SMr4msprrDcnmbQP6T7RC0hP+7w2weoG/QLtoY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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