SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '412603b17ab0f679c5b81503eefb3098f21d4585769ba2ce6b287fead51937d7' 
  AND token = 'khQJ+LBwi+1lDvLGuBI2UK3aHtgD3fDkUxpoRcONM8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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