SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd31f8ab1ca9b7ff38485853d16dc309e669158d6ef09e47f35b7a34b43928d40' 
  AND token = 'qdTDynXC35ZhBf4KjQXB++y5lY2Dq+oFswf1EVnXPjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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