SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a1734ff4234fa05569d9db7adc1303707920900ea5c2a657261824d00c2df4a6' 
  AND token = 'NKEkN3DHGCwASjI7KinaY3IP201XXAIDPZhRtZRuoh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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