SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0724d59ded4821e3232ece71e467eb7802aeba551b9632bed09940c766da5b23' 
  AND token = 'su4Q7MfZnFHPakq6KDuY9aLvmAovr0wNAl+lUgRozuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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