SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '411503b5f60a70c8d8a3402e85afc7dde47266019e49cda653f0a1c21f0a6f2c' 
  AND token = '8axzrf8fO4+9oDmVUyxiIo4ikMxRlyHttkniGXGvWuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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