SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9983e46f76d013f8a8b3bd577f1c4cf39e26b0f3d8d92db8b43c78c0501e67dd' 
  AND token = 'Fah2zxxPf+36RxIioGsRroXO6Qv/HToEUvd0vLtnLw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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