SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91528d90063e9dad413d86192a7df532c27ec38058374b48491270eb98b8cda1' 
  AND token = 'OI0R/5nYSsGMYaJD5497wN+kuiupGZxSjcsTT8L7Kz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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