SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fa6c7bcc47bc1532fcf556f8ef5dd814f7e9f00619f177256751aee7ec1ecf3' 
  AND token = 'v91gTzEAmxDnh5honTd/0UX9IqMeMXbQQWNLCJXOggg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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