SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b0e9f58725c7c6c4d1e331f33b231b510cf77de33cfaa946768b51e7ab22be4' 
  AND token = 'pM6foJr2VoN5Zy6SfuYm/UvZnSYrzzFjtABmuKNq8ME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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