SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0f381fc51118baa6c6bb62b6e1b9881b3638c0ca75659f6875a73d4dd83ce14' 
  AND token = 'NClmhWgKJ5a7qGTRy0hST3EdZOkER3uLPwf6BblXLlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}