SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47c41654e0daebb5817921d6a016168ddf819debc5ed1d10eb33ccdffeea6462' 
  AND token = 'oBn2oMS+vfQ9EBEcPkjbYikSpc+Yy3UvZAQsvAuO30s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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