SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcb43eaab54cdb4807911e58db61cb3a27833a239f459eb09ca7820cfc22bf64' 
  AND token = 'zkFcXpoSPkHSMABYSB0vyMuhkD4T7Z9mvZ0PQP3uwHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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