SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88fdba311f9963f3280a2e1a01a1b9fe209e056f3b1b944a062c27e57bf62cd9' 
  AND token = 'QwhZPYbTv0O2dGhck60hK6XCccHq6wAXUAioJPHtWXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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