SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3d269a7593bfc41e9a4ed7de7b3f7e6ff43525dd8ff8e2aeff09c1c9d2925c3' 
  AND token = 'gcFWnBFKMAroHOK4w5WrKEjdZYTI9zvYhm1WXZVKhGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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