SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aff48aca1ad93dd49794214f392beccbdb9ed4c95bcee14e4504c3bbe95e3b7' 
  AND token = 'MMUUrhs/2C16Jwk8sa7e/fcmieHVg9pHDT4G+tDKcbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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