SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61d28f6270fbc0990edcd20661912b149a66671367ad7cddc10e9633a72d00fd' 
  AND token = '8Bf78G0GiF/fmdEtGUwTjxkNWwuW2jaoBnrTVsnaPfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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