SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69858cedbec97a38db98cdfe370d6d3981f12219e0773a7fcc811015213f29fd' 
  AND token = 'Zt0BXKIpJ2rowVVAqi4fFXwBpY4HEB8JkteRZnNJtmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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