SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bdbf34bf16add257f138c3b7ace7904ce9bd73c01cb35fe44bb98483786774a' 
  AND token = 'P4pPcYTl3TiwvJvLWYCpCPs1MgL0OrU4fESioF1fNCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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