SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc12ffa2dbeda456bcc5bd59bd0476c336bfcfcc6dcedb6ce3981a79e91de970' 
  AND token = 'MQlOZNB1Z4PdxSRs1uno2fZ/SPZYHz44DlhWDg34d5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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