SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad465a79f836b7f8109e2b8c80a0faefb589434bf24bd758df1ae0065d55fff9' 
  AND token = 'VcTUZI/p/1V8qKY+UkfLZxYx+B38Xx4UBJDudm5rC1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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