SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbebd34fee8dacaa7f702bb8fbbd3adbbe1543e9188c84b42b6b2126365f8941' 
  AND token = 'VPHuLh8PbSrKaaQ6fGMsor4xB48+5ll9KllVElc1q6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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