SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd71f1679f20f465f7349469e5d9fb502b4b645f917dc7f1f79d34c3f4a28b92a' 
  AND token = '1rULV+d0J54e/Z8jNhsh7HTpu1goW0qH9qg1ZHEv0B4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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