SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fecc5e3e9a07d73212fb2fed9bceafd96d5997fb63777ab6476202e830753248' 
  AND token = 'AOoZ7r0PiE62lMcP96ELgBltNcTBocqm0JOur/6kxDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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