SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bc36dafab433529b1f5821352b2db45adb51914a8fdbb8bcd76f7a653757850' 
  AND token = 'OzcChzaUFA2BUZoRM+tWeyXRvOLnv/XjO6LZCbGTsbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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