SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ff625658d2f4efd55c13304807a4524a4744375d47caef741a311b55a29c176a' 
  AND token = 't5rqT6Wr0YDEi24Dl/gqqZ1FtSDABQyvkhmJYu1ZOE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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