SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4f64df525cacc3ecacafcf6e83c0aeecf250b355fd68cd9f9c525542c8eb7062' 
  AND token = 'TjIda9X+uui87/2pAj03LUB90deiv8vkBORR3NgwQDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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