SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1aeb7a1c66124377ac13de56898816911a7745e273174f8144c92b7f0f456d42' 
  AND token = 'Czk6cTl3no3niCDMJxOebyPBxKyuhw6eBawM8ZfI7ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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