SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ec4351f529a5302517a6e058ccd9f8b3d0aa560f0b61f84e35cb180d3d8b6a5' 
  AND token = 'FbASd9Wqaoa0dAvUgenjeR3GwgW2q8EEQKCVea0da+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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