SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd02a18055aea461b7fce871d9de38deb308bf5479fd4113b220aef8b4e2ac6' 
  AND token = 'V3ZFX5MCDge82LOBxTCp7GQKbE7kUiIsr0+MD04pHOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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