SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f836d2c543e3b12f3313d5f1e09861ef90a581d789c37f2bc41a3780de86d16a' 
  AND token = 'wsDhyMebRWs64EQckv0T0tpc9nSj60jQsurXaFlrnok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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