SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd506ebd5e0537ea567ce9f5fc8d9152e31f85179c94966a84be8c494b50f8d8a' 
  AND token = 'iTu8/jOT79A47uAe05DyFyMv3nyBL9eVnr1KVhG6Cm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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