SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2463cfc609921ebbcc4e4667992854cd1fbfe66529c970b7d2a424738031bc7' 
  AND token = 'hECI5hmRuJ7Q7yxUxgv3HNoR9+4yzBvuMWfL1zqK3aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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