SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79658908dff78970484b63c99aa809767015f3aa66f4b7ebbb0f6230f14fa22d' 
  AND token = 'pxBONsfRcODgUHEajqhc/uRqW3MbaX4UOemqoBo6GtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}