Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6e6136bec754876ff52fe598feb48f3d0999937090b9add1a5954fbfbca9cbd' 
  AND token = 'g1HCCSq9i5QFp4fTvi39Jppg9QST38mIa1XQbySgZgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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