SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63847fedaf378dd48ee1373a7269d0b5514054655e28f7b02d66d48ce19b412b' 
  AND token = 'FBUnC3opFOVFtD3pghxnxUdju37Xbf0JYb/hfxcWvsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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