SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3edcd56f93ecf474da8df9127f56f8de477529b4107730a032a81342590a393e' 
  AND token = 'XJ8aJP52Ka5/RGhFwxd1fsi8FpHrmveh3tZesbsH+wA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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