SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5395138b748db24eae4c80548318c19eb3c8349019b4685a8255654ad0b5bc46' 
  AND token = 'WcRHsvek8gATUUPqolR3Ae/eUcno0tRUrWHqfv0BwQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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