SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17ef180f2dee9b160c07c2fc7f6439661acacf42a78c1879fbe875c584a6f96b' 
  AND token = 'p0vAmAz82+egbonidJf5zPwObQK/Xlx9bfG3BFpHvK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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