SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '131b581a77de93a4e4c7620490182a3ccd21790b3eedaacce86c59130334d3bf' 
  AND token = '9HlPe3fd5sIPnjZGNX1DzQky/E6CqZGKRnIDVUo2gmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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