SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd26a0735bfc05ddbb0f688f22aa2b4b90039a96bf9b774db959415f83f45afc' 
  AND token = '8EszP7XX7GS0VOUo7C73j6bfRuHHTuHBY/JS4umpeiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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