SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c54706688764bdcde5612b34182b23bb8ed445235cd754e957596021fff06b0' 
  AND token = 'Yi7C+Y3LRVCRNe2ghjQcwj+KVzX+eOqXZeSlavPtMXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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