SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e274bbb867d0fb99b549d84a146b1908ecc5756fd058bdc633610212ec10085' 
  AND token = 'gjUqb1sRL6R+lMWK0wryodtNMZTtpygaqNGKH/gH7r4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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