SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2624214b6fc3923df56a18f584d2610d960499f72906c6fb7c773be907580073' 
  AND token = 'h3OcTKgqPCQogzPOaJF9mBe+qOVt0cjA95mQEHjE7Wo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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