SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cae5fe4a42a67057aba3cb4adb4796f5223d9a41f5c756438111328518f9597' 
  AND token = 'SY4WLxQQQt6eXB/ALgChbilu/wiKEoBZ3y27YO+H/5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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