SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c5a1d71ed4d852573a3f63c37798c95de9fe333933a8eb242541ff652125be1' 
  AND token = 'ZcrW71daWP1V7rsfSV54aYZor6QWkKmZILEDXTBHRss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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