SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3044c28c4a67f4fbc9f36524b55ed8282d0f297289c33eecb3291651f3affb2d' 
  AND token = 'c/gvkBGd2SswAJLYYDb/hw7Lsl8uK1hK2mgCqa6Mt1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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