SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'def24d0c814b5f469f7e181e27019fa4a2608373ef5da1f2ee795ac5ce2085e0' 
  AND token = 'BfX53WQJPvNsBM9eJO3ncKLxKAvPRHbeuv3QexlGa7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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