SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6e4e48eb1533199953a3488cb980c30e7d9ca0b6fe3c5b82f1411ecd07765e2' 
  AND token = 'Oa9XKJ2z69w1s+YWxvqC/4iDGUhhvvlqIlNEcZ6ux9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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