SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbbeba69c5350385849cf0570a9e65c4138fa9a89244ead6c7efd34d7956d487' 
  AND token = '4GwJB6WCZznUni8pTZdo+Ss/dOVZFLv+e4q2ckR2DWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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