SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6ccd2695092b3cee2f78fd8741e89eb94e9a2ce897a97ab0d5722ab78996ef5' 
  AND token = '9bMYtTajvIPCZtFLpaSfQ/eKCkXpWqA6TtJOy5K05U8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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