SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d5a69343f67eabb71f6dfec2ae47fa8563813197ffaaa0f72be2e9096738cb8' 
  AND token = 'TtbG+mQtHLB/l+c24GV0jGeRlZGrvG5+w99323PqDL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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