SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13e65f154240c204a87821a947a93ed82d716c5807215a3eb7910de73bb403a7' 
  AND token = 'n9LXe0js3FWDoTeGzJNcNzFwkvFW4bkpc8mFYNKVJmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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