SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e25be3f1d28194d8782673bb7630d23566d271f374e16ff3c4f078477759111e' 
  AND token = 'zxZP9RRmL7JiC25VXPp9c/pI/u9Ohk+HyCTnNhT+ewM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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