SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bebccdced4fd1d8d241c2b5694156094b14255f1dd7aa136784f052c16132742' 
  AND token = 'vKesyCVyZRPvVejJwPRf1Ic3F/QVCHKmI0/HF7UsdGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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