SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1667c1af1b316e39256787dd949565f4786ca46c350a85e30631b8193b5145ce' 
  AND token = 'ZBN5qrrM/vAtk265VoatKpJXqK/p9Rk+StjXxYFCvqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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