SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '547680bcc3e6b32105a661e5787df9080332c8ea6afea5d9d86ffc136e4cbee5' 
  AND token = 'vioRmPSjoX8swRa7dr19XVu6OLwZNpNqcSvI3ygwPII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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