SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e19620d7ffc543dfbebe30857b250c1dcbfb58ae714ecbb9a99d361ce82aad71' 
  AND token = 'BxzPXyKQLl9eO1kUXtbEIWyUr9TmJMm2icudniJ5Lt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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