SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'becf0a68866347adc041a8ce444f388a72a8441a955176d20c40845e86ddd280' 
  AND token = 'VPrNj54bGXlc8hRIgJcp3RaiZ+cWjCLRkojLpspUkiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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