SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '385bcfc9863931da700cc6e035de62321a10bd9aaeaa5c432b2ea54fe2710ce0' 
  AND token = 'sxCnX0oMz0A8qMm70k36j48xRFY5igpBP13Yc9xzD3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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