SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ee14158fa425a43fceb1bf63950d9c5f35d03f489aac68038d28e6c86b5f6cd4' 
  AND token = 'B51A3MdWOqUz4UknHdgG0DxPab/fuEaa74chlJpG5tk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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