SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25c91c23aba8cbdc9afa50cea8ac6a67bc307bb2406460d7a74f9154fd26c478' 
  AND token = 'VlO8aiX8ExdPFlVXHMnDvcagm+c9UJzEiJO+pL1g9iU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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