SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95ddf29a8b87f663ff591a1294b2315069ffabe4913283f3b859e1e657ba0a1d' 
  AND token = 'TyGm+/VRuGxKOJ9JyGZV8ysZJwDPLLXN+6Lm6m+anU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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