SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '531583c41d4eaa258e084686477658adc58e43a1cc609e6cee9e6c38f44d4c5e' 
  AND token = 'CW9G8j+2qXaX6l0UuxoFBQS1zGq/pcorJo7hX5ppbIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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