SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1db9cc4ef032281aa760c89c841b532e9f2a715fbf03c8fe5b9fe195ceb2fe12' 
  AND token = 'MIpIoFfpY/e/oOoteO+BOFpfpCopEU6apLpklGZxwD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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