SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71ecc98fbf728f56da4125d8ce4b9a00bc1f72fdd9dea1778f6071351afb568d' 
  AND token = 'Z4DApKuKKQqO9xhgBBYtmn3pGY2HZJdNUsE5IbMVAzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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