SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd9f5c61f3214da4392d6d7fff567d2d75ea65a47b7904a0b6d8105351c6e955' 
  AND token = 'MfGJYjt3zs2Kzs8LAhDoQyGMQb0hV7m/DMJuTFuXDz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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