SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b473721be4f04fd9a1e303a358671ffe18b4b456723f7c257a6f37be3c6bf09' 
  AND token = 'Dq/q5MTwhuvaB9/vIkaRaz1fJR3mW+ma09/n8HAGooA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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