SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc715ccf8890645e1735b9cedc1348de28460daf18ed54130de022664032d3af' 
  AND token = 'RrjLCUCxMK/tmXiQ516kX9qFWwBbBF2/wmUzHG2Dlwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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