SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5648c6e437b4e2a0ce94257dcc6dc3caa746ae55e6cf1831d616da51c6ef8981' 
  AND token = 'yTNOQ0yBWO9sosCNkmhUXyjzaAqmCFMZwgXYEbbK15w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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