SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '609385092b442e5ca57973b528a7f81a959751c4f4b90ddb98f1e5ac2aec3957' 
  AND token = '8fECm2LD8XpMZnBjbuu2zzubiBYXtsS0zZKYpVe8ZkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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