SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e23d7b4b1a77b47fd45e3ffecf49a8d6fe560f75fddcc55a7ced8a4b2b089a89' 
  AND token = '1gqn5VR4WyjvOtNZJdn29EYumLWsbEGG8FwPrhTWtYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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