SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '235b0d29dd53408551a7ad7883b014f061ac979461029f363127979207abe5bc' 
  AND token = 'jSZWAVEZdRru15NQ4gGj/CbFy/CoLT5aZ3kM2DJyY3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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