SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7d0f3c955357978adce4b493de0297626483acb97762dacd2369a8aed6bf9baf' 
  AND token = 'rWSZGCiZ9xo7qqX5WOnmchnkw1cewx+D391g2vjtS6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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