SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec79dc711f9d679fa0f9ffdc18c9316b0e8825218b1fdc6a4b8df8d3a3733050' 
  AND token = 'dZxE/jGihBzkoHU1BNRxJeit+zBJkuSsd/UOvwejC+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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