SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c81c8c3cc30f216a59b1cef4a4523c3ff2bc134562d4ef0638cad08d36aa7001' 
  AND token = 'iSbqUUjEuT8IniqGBhYKbFL4H989Ljz5LWF8B+Zv3dU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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