SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4567fede49b2620efe676c43855e1aa8da68866341fbdc4de50d704ba8ed0fad' 
  AND token = 'ORuIB6urwc+xWObfdcGXvo5wr79JSvUVicdE8CXCJ4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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