SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95fa3d8e9a3bba63ccf79fcd640fecb92e77078323e5172262b73b1076ab4225' 
  AND token = '+dkiD+jRVWKUkL9BB1tNL6nA/LC/hwUYJo76qwBhjxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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