SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6819b1f706dca8c3f061735f84bce430a26b197f722fa71eae23ab8a812c5ef4' 
  AND token = 'PvDc9qE6DboDaOLwOgr2vnIinBrHkG9R41LX2ChZbqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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