SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '560406dfeabf1144fbe37ad699d0b6e431a9b729f02a01795fde15b9ffe4035c' 
  AND token = 'TMiJNpeTLv3XgmMAW7YNcKHWXQ61QnkLirivYDvdbUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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