SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69bd2228271b7976b965eb3dc4ee130cb49c03e5395304755fcc921093a7bdf3' 
  AND token = 'GxvSRoNcUIj+J5alrkZMEJRW3Qku+/tLcupGHZw0TZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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