SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e2555f9c1c217d664e12ffca5c1f46fe6c89a4ffa68139ba09c863cfbced3ee' 
  AND token = 'oRHOca6OizlqPD5zs4fDeIhV5Mh+VGW+h/ogpCatXOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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