SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9e8492b42de553e56a3a24599f9e8ea3a99076f5183f78d5e936c12591a02d4' 
  AND token = 'B/Z+zdcVdK6YX4Sqv1nTw09JLGNtAhc4dhz3Q64qdSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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