SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bfb315d068011fe92a3c2d6c348c9d318cfd64b23bf46a43b75bc88d04ad5b9' 
  AND token = 'L9BvwZ6AUo8YMexU53lj8pPTc2vRiqgeqb9BwwpRij8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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