SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b71c667728b516a35815922ea465d701cb6f0a8910ad90a9af99ed3b4cf62caf' 
  AND token = 'LZIg109sXlz9P4sVeOUqtRieEpPwGtZ47ZnISb4ifw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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