SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cceb56a822a3d338f525c04b6565a912211d2bace5a96af6cbd117fe5017042' 
  AND token = '38/+6r3DDwUyHdlFEP0FbLZd/NBVMEKEeX8tUpdT9oQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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