SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5ca89ff8424a02a748ea6eb983d416af23b44fc1bea06cdf75f84df761cc0e1' 
  AND token = 'bG1XgomewsCdEKkE1ABprTONv9Lj8pSvAW1GDYOksPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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