SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4dd8cd3d86085a1799799c048f8f08122ac67a60fccc087fcef1c9c3ca01bce' 
  AND token = 'k/zdQYic7bZJSV0KkWSQuJfskhNzcMS+enH+MefJnio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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