SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b69806b7fc22fcf738bd922a5fb48c91089ac09154953a73fc1bf9b3a4a8cba' 
  AND token = '0zJFeAHDqx3YIArmWvWm6zMCtlnRgwjefIBIL6jAwx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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