SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b8522136757139ddfd08e7f5deb7ee74b6c40400a21570018555eb980688d5c' 
  AND token = 'd0oF49V8YHFdDUcF5TO5fjMj56zUVPFWET/BNCbMnYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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