SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef8385b2d444025d9276f6f083dd8a67e972b8ef1fbb636a387930bf6c1e2761' 
  AND token = '0l34xyBB3tGSflDH5RIIwVDnhJi02PRTPuGBUAnENMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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