SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c666cf352c78301bdf5984c492eaf27e636808559f5dd00b4fc6cd662eb13a6' 
  AND token = 'kc1WAS5Mz3dpojp24G/Jx7pMqdp1s+UgbOFIlzNTm0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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