SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70adcc6ded7bd8bad9f61d9756f630b812c0c2e5017cc66401116616335bc37e' 
  AND token = 'aIMLO42dsdccsyRh9eGTDe14SmDUrUS3raqyAzbzImE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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