SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '815a0fd1aa18c17d55ca5abe08dddc916b8e287e13d86c33a2b70254bf336029' 
  AND token = 'WLfA4XszQHkWMrSTZCBmcJvYCmAHxc4cRudJa9FfF6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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