SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '323f46239f9d819ab4ba514bde43881c47db714f8c449e7f6591ccfbf5c0d666' 
  AND token = 'O/6GOB2vmAjsuQW++fFW06Z7NERgTspWzYs0UA7emlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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