SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12bac3ef8ae35aa3202bfffff2a0df417cf953142a8523ff5676c36de698234f' 
  AND token = 'q9Aeql5pH5qWDsgw33XcnxlhWE2rDJEiMJqDRDpLOfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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