SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3ddb9ca244064b6dae683e63a0bc600560f262b760ebb5165a7302f9f586fb' 
  AND token = 'Z8zxq/RwLTLo+qU3DzGX7EBPWCL1m/5hPnLdnqP+wKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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