SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fc07befbb429230b5c7b8bced34ad1ffffdf865a7d5862394cddb2ab2694fe8' 
  AND token = 'g7LqQLqr+qZPWSQXtlhPOutY+vAdBQ/EgjHnt/OrOcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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