SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0b660071032249baecbebedc9fa5c5f756fab3c26ae9d2f3367d9024a35c81' 
  AND token = 'H4kQLlyqbUqzgiWn9Oh8FRTPpFWR2p4eaiwGBlHWiuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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