SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a9dfda5ebd4acb7a764bf52c1ce9d9b1dbe917cc4b1dc7549619871b646badd' 
  AND token = 'O6P/SDt34lbFzgZPn0/o0vGUd4p4YJLMIAdHZVQZuLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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