SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '450306cbb4c36afd8dffaba30cbc9eb0d94731aeae412d10ad8c74edad284024' 
  AND token = 'LJrfXqtoO0CD1BKQ41dENDjVcTEQ0hwJ8t8N0P4XIr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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