SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ba220a1163055a424f8e09956fff478d124e331622e5f900795d125af6bd212' 
  AND token = 'prFsZyQnVy3RDVN2bdRq4IrLVijXLyIcUwxWxwj4O7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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