SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57ed51754d27396a83fa81a91e2ff62680a8dc0ba6a9f1746551fbd8ca2c14a2' 
  AND token = 'zRMlb9aw9gvGC8uw1ao5mkOyaupuRvLg5RxbUKiYWXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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