SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7c4a4dbc56bcf9c8c12f8a540963920e8037439478193cfc03a80a7ae84fa78' 
  AND token = 'mY9DVAUmLkPPwLVvKU/NrbU+yLY66OUN+V2IMSgniZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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