SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f2386fcf552a11918498a446c1fe23b44618470de79216a5ab47b528247aee' 
  AND token = 'QLdaNvzHLCu76yjkMbdKU+zD0jnJvUnd2u9SsS0GI00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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