SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc6f384f29e3bf3ac90653143cf1bf2bb5e5a325f243d322dddf86e35085be6b' 
  AND token = 'VZQKkE9OL3VGlK1WioPazg6MhZk+TQmUberiBfKn9ik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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