SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56f9be1d96cd0481bead5bed462f96b8209d9f647d390e1fd6660dfe375a7711' 
  AND token = 'JZXJYdpCEHp2DyFIPD/kjlkO7nZ8T7VzOu3RihyjRGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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