SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc8927b0aa66a52a2167bbee8997350c2390c4bd75d80b9b8e1b251af65d9483' 
  AND token = 'Ks6uw1PSPkvBe8ZUDrITZ/1NUlHtHmqvcIDYnhD8XdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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