SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0505b327605f5d510b44711ed067b9d89b9c816158f7c8e53cef01b5a0c3fff1' 
  AND token = 'mdyuNPfxG/qKqJFux4wt56p+TQyCPKNHKngsgQu1whw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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