SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d57dba6a9e76837319d50b951b8adf90e7d308408dbd0bae8301057afc61239' 
  AND token = '+b88o5J39djjM5dQrRlIPtVukOFz21T1ygG92w2Yfrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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