SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6708dbeff8ed9d85dcf88c8c5de81b9b0a106ef63e9e106299315f19bdf33f8' 
  AND token = '9CiaBp1fYZnn1nbK+UwdlKWu2aQZ2MlWAaydl6lKHk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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