SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1582a4e629d7dfc61fe743e0919ee2d6d9df933fc69db00bcc14f4eaad8078e7' 
  AND token = 'RNbEflci+PSjr1kPmctW3HfUsE9qiEcpMR3oez+1vBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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