SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e2a5e90683a7c1ac8ad0725fc1772f2b3d6168e30ed8c58b886a877296394d23' 
  AND token = 'YP8mKZgdZDFdXLJyKqh+AUqtSOP6jXVkZwo0IdEA51g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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