SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8de182135abf0755aee1d7f524491ca9dcdaf294d2f173e36fdf6719e7de90c2' 
  AND token = 'Ermm0LxDw5aA5ErkC6JWNyhEJHFzjtES8VlxZtjGcyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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