SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3105387d7843b5ce1eb276f1906ed8e75e7071f19e26de3c39dfc8560e21ab6b' 
  AND token = 'xd4MfACIzTklxP0YbO/NdCfFuncmbLu6pmkhFJuIg+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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