SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af63f187823088b8dae238684529fb896093dcd5a47e1d1908b83b7ce45de1b' 
  AND token = 'LvvTEZiaeUg2LhvWIKL2tbY3go+RQKZrq4ztZRBAEFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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