SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3827cddfe148253d410969707287113d96a547cf11c64e97d15baa89c94de89' 
  AND token = 'WquGvKMslL++Vyxmgx5Fv8mtrmh2V1/4E/ckNCwm49w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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