SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ade2ac7cf608a39fef2f0cef2359e0b50c643c1eb3fcff77416da1dfdff7301' 
  AND token = '8MHhjHAX/d4wXWUBzQ/WO24qaJ9X6BZLdM+/XoumUsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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