SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e83204e973da1be27d534b16d7e8ed3f7bf223ce21337cbc79cbde09d4db3008' 
  AND token = 'V8lOkm4AvukCP71lXqWJLaFbqbxTzKWUYoJT7o564BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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