SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef023434f23a9f03416af0a50787bc17b9f214c929cbb0cdced29e406554201c' 
  AND token = 'r6lheNoI1QUHyO5zA1qzzvhydMrmrxgHTRrwS71tsv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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