SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f0c689c2dbb5ca26d0d6929551685aa21a27277df5f5b75ecd3cb5e782ba4e1' 
  AND token = 'V1pRFxV8vruxy/ul1ARhWtT/wYpak7NhGfbWUk6wpuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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