SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e7053463f73fc21199b7644eba73ccec24d991e00e2d242e5e9e6aeb4c334df' 
  AND token = 'AVBlYks7qJsfiNJFE0Gbu2obkTJKKA7TomdEvQr2irI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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