SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90f05b47840e5fbe6c21e811200ca2fbe9d2c4624058e242d9c038d1d755fb6b' 
  AND token = 'e8mGWK1joHzKRaA1ueVh/VGpKWb8sZOqJWANjFg/m7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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